Respuesta :
Answer: The molar mass of monoprotic acid is 126.1 g/mol
Explanation:
To calculate the molarity of solution, we use the equation:
[tex]\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in mL)}}[/tex]
Molarity of KOH solution = 0.300 M
Volume of solution = 23.00 mL
Putting values in above equation, we get:
[tex]0.300M=\frac{\text{Moles of KOH}\times 1000}{23.00}\\\\\text{Moles of KOH}=\frac{0.300\times 23.00}{1000}=0.0069moles[/tex]
The chemical equation for the reaction of monoprotic acid and KOH follows:
[tex]HA+KOH\rightarrow KA+H_2O[/tex]
By Stoichiometry of the reaction:
1 mole of KOH reacts with 1 mole of HA
So, 0.0069 moles of KOH will react with = [tex]\frac{1}{1}\times 0.0069=0.0069[/tex] moles of HA
To calculate the molar mass for given number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Given mass of HA = 0.870 g
Moles of monoprotic acid = 0.0069 mol
Putting values in above equation, we get:
[tex]0.0069mol=\frac{0.870g}{\text{Molar mass of monoprotic acid}}\\\\\text{Molar mass of monoprotic acid}=\frac{0.870g}{0.0069mol}=126.1g/mol[/tex]
Hence, the molar mass of monoprotic acid is 126.1 g/mol
